U.S. patent application number 10/735693 was filed with the patent office on 2004-12-23 for electroluminescent conjugated polymers containing phosphorescent moieties and the application thereof in led.
This patent application is currently assigned to National Tsing Hua University. Invention is credited to Chen, Show-An, Chen, Xiwen, Chen, Yen-Chun, Liang, Yongmin, Liao, Jin-long.
Application Number | 20040260047 10/735693 |
Document ID | / |
Family ID | 33516543 |
Filed Date | 2004-12-23 |
United States Patent
Application |
20040260047 |
Kind Code |
A1 |
Chen, Show-An ; et
al. |
December 23, 2004 |
Electroluminescent conjugated polymers containing phosphorescent
moieties and the application thereof in LED
Abstract
This invention provides a new electroluminescent conjugated
polymers grafted with highly efficient phosphorescent
organometallic complexes (such as iridium, platinum, osmium,
rubidium, etc.) and charge transport moieties (such as oxadiazole,
thiadiazole, triazole, pyridine, pyrimidine, substituted or
non-substituted tertiary arylamines, substituted or non-substituted
quarternary arylammonium salts, substituted or non-substituted
tertiary heterocyclic aromatic amines, substituted or
non-substituted quarternary heterocyclic aromatic ammonium, etc.).
The emissive polymers (fully conjugated or limited conjugating
length) covering the full visible range can be prepared. The
polymeric light emitting diodes with these materials can be used as
indicators, light source and display for cellular phones, digital
camera, pager, portable computer, personal data acquisition (PDA),
watch, hand-held videogame, billboard, etc.
Inventors: |
Chen, Show-An; (Hsinchu,
TW) ; Chen, Xiwen; (Burnaby, CA) ; Liao,
Jin-long; (Hsinchu, TW) ; Liang, Yongmin;
(Lanzhou, CN) ; Chen, Yen-Chun; (Hsinchu,
TW) |
Correspondence
Address: |
BACON & THOMAS, PLLC
625 SLATERS LANE
FOURTH FLOOR
ALEXANDRIA
VA
22314
|
Assignee: |
National Tsing Hua
University
Hsinchu
TW
|
Family ID: |
33516543 |
Appl. No.: |
10/735693 |
Filed: |
December 16, 2003 |
Current U.S.
Class: |
528/4 ; 528/380;
528/423; 528/480 |
Current CPC
Class: |
C09K 2211/1037 20130101;
C09K 2211/185 20130101; H01L 51/5036 20130101; C09K 2211/1466
20130101; H01L 51/0085 20130101; H01L 51/0087 20130101; C09K
2211/1088 20130101; H01L 51/5016 20130101; Y10S 428/917 20130101;
H01L 51/0039 20130101; C09K 2211/1029 20130101; C09K 2211/1483
20130101; C09K 2211/1416 20130101; C09K 11/06 20130101; C09K
2211/1458 20130101; H05B 33/14 20130101; C09K 2211/1475 20130101;
C09K 2211/1092 20130101; H01L 51/0043 20130101 |
Class at
Publication: |
528/004 ;
528/380; 528/423; 528/480 |
International
Class: |
C08G 061/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 17, 2003 |
TW |
9116457 |
Claims
1. An electroluminescent conjugated polymer comprising a side chain
comprising a phosphorescent organometallic complex.
2. The electroluminescent conjugated polymer according to claim 1
further comprising another side chain comprising a charge transport
moiety.
3. The electroluminescent conjugated polymer according to claim 1,
wherein a backbone of said electroluminescent conjugated polymer
comprises one or more repeating unit selected from the group
consisting of mono-aromatic group, bicyclic-aromatic group,
polycyclic-aromatic group, heterocyclic aromatic group, substituted
aromatic group, and substituted heterocyclic aromatic group.
4. The electroluminescent conjugated polymer according to claim 1,
wherein said organometallic complex is an Ir-, Pt-, Os- or
Rb-complex, said organometallic complex comprises an element of O,
N, S, P, Cl, Br, or C, and a heterocyclic ring, which coordinates
Ir, Pt, Os or Rb, wherein said side chain further comprises a
spacer which covalently bonds said organometallic complex to a
backbone of the polymer.
5. The electroluminescent conjugated polymer according to claim 4,
wherein said spacer is selected from the group consisting of
alkylene, alkylene containing heteroatoms, substituted alkylene,
substituted alkylene containing heteroatoms, an aromatic group, a
heterocyclic aromatic group, a substituted aromatic group, and a
substituted heterocyclic aromatic group.
6. The electroluminescent conjugated polymer according to claim 2,
wherein said charge transport moiety is a hole transport moiety or
an electron transport moiety, wherein said hole transport moiety is
selected from the group consisting of a tertiary arylamine, a
quarternary arylammonium salt, a tertiary heterocyclic aromatic
amine, a quarternary heterocyclic aromatic ammonium, a substituted
tertiary arylamine, a substituted quarternary arylammonium salt, a
substituted heterocyclic aromatic amine, and a substituted
quarternary heterocyclic aromatic ammonium; and said electron
transport moiety comprises an oxadiazole, thiodiazole, triazole,
pyridine, or pyrimidine group and is selected from the group
consisting of a monoheterocyclic aromatic group, biheterocyclic
aromatic group and polyheterocyclic aromatic group.
7. The electroluminescent conjugated polymer according to claim 6,
wherein said another side chain further comprises a divalent
radical which covalently bonds said charge transport moiety to a
backbone of said polymer, and said divalent radical is selected
from the group consisting of alkylene, alkylene containing
heteroatoms, substituted alkylene, substituted alkylene containing
heteroatoms, an aromatic group, a heterocyclic aromatic group, a
substituted aromatic group, and a substituted heterocyclic aromatic
group.
8. The electroluminescent conjugated polymer according to claim 1,
which is a homopolymer.
9. The electroluminescent conjugated polymer according to claim 1,
which is a random copolymer, block copolymer or alternating
copolymer.
10. The electroluminescent conjugated polymer according to claim 9,
which comprises a non-conjugated sector among two or more
conjugated sectors in a backbone of said copolymer.
11. The electroluminescent conjugated polymer according to claim 3,
wherein said backbone of said electroluminescent conjugated polymer
comprises a repeating unit of fluorene or benzene.
12. The electroluminescent conjugated polymer according to claim 4,
wherein said organometallic complex is an Ir-, or Pt-complex.
13. The electroluminescent conjugated polymer according to claim 4,
wherein said heterocyclic ring is 2-phenylpyridine,
2-benzo[4,5-.alpha.]thienylpyridine, (4,6-difluoro)phenylpyridine,
2-phenylbenzothiolate, acetylacetonate, or picolinate.
14. The electroluminescent conjugated polymer according to claim 4,
wherein said backbone of said electroluminescent conjugated polymer
comprises two different repeating units, each of which comprises a
side chain, each side chain comprising a phosphorescent
organometallic complex, wherein said two phosphorescent
organometallic complexes are different.
15. The electroluminescent conjugated polymer according to claim 6,
wherein said charge transport moiety is carbazole, triphenylamine,
oxadiazole or triazole.
16. The electroluminescent conjugated polymer according to claim 7,
wherein said divalent radical is a decylene.
17. The electroluminescent conjugated polymer according to claim 1,
wherein in a backbone of the polymer a repeating unit containing
the organometallic complex ranges from 0.05 to 100 mol %.
18. The electroluminescent conjugated polymer according to claim
17, wherein the repeating unit containing the organometallic
complex ranges from 0.1 to 20 mol %.
19. The electroluminescent conjugated polymer according to claim
18, wherein the repeating unit containing the organometallic
complex ranges from 0.5 to 10 mol %.
20. The electroluminescent conjugated polymer according to claim 1
further comprising a crosslinkable or printable functional
group.
21. An organic light emitting diode, which comprises: a positive
electrode formed on a substrate; a negative electrode; and a light
emitting layer disposed between said positive electrode and said
negative electrode, wherein said light emitting layer comprises the
electroluminescent conjugated polymer according to claim 1.
22. The organic light emitting diode as claimed in claim 21 further
comprising an electron transporting layer formed between said light
emitting layer and said negative electrode.
23. The organic light emitting diode as claimed in claim 21 further
comprising a hole injection layer formed between said positive
electrode and said light emitting layer.
24. The organic light emitting diode as claimed in claim 22 further
comprising a hole transporting layer formed between said positive
electrode and said light emitting layer.
25. The organic light emitting diode as claimed in claim 21 which
is able to emit red light, yellow light, green light, blue light,
white light or light with broad band containing multiple color
peaks.
Description
FIELD OF THE INVENTION
[0001] The present invention is related to an electroluminescent
conjugated polymer grafted with phosphorescent organometallic
complexes, and in particular to an electroluminescent conjugated
polymer grafted with phosphorescent organometallic complexes and
charge transport moieties.
BACKGROUND OF THE INVENTION
[0002] In 1987, Tang, C. W. et al. (Appl. Phys. Lett., 51, 913
(1987)) reported an organic light-emitting diodes having a
structure of ITO/Diamine/AlQ.sub.3/Mg:Ag by evaporation of organics
and metals, wherein ITO is a transparent conductive indium/tin
oxide as anode, diamine as hole transport material, AlQ.sub.3 is
tris(8-hydroxyquinoline) aluminum as both electron transport and
emissive material. This device has an external quantum efficiency
of 1% and brightness of 1000 cd/m.sup.2 at 10 V, which motivates a
rapid development in the research of organic light emitting diodes.
In 1990, Friend, R. H. et al. from the Carvendish laboratory in
England made a polymer light emitting diode with a structure of
ITO/PPV/Al, wherein PPV is a conjugated polymer, poly(p-phenylene
vinylene). This device gives an external quantum efficiency of
0.05% and emits yellowish green light (Nature, 347, 539 (1990)). It
indicates the beginning of solution processable polymer light
emitting diodes. These devices utilize only the singlet exciton,
wherein the rest exciton in total 3/4 as the triplet is not
utilized. In 1998, Forrest, S. R. et al. made a high efficiency
electrophosphorescent organic light emitting diode by using
platinum organic complex (Nature, 395, 151 (1998)). The triplet
state of Pt complex has short lifetime and thus partial singlet
property because of the spin-orbit coupling. The iridium organic
complex has even stronger spin-orbit coupling and can emit various
phosphorescent colors of light with different ligands [Lamansky, S.
et al., J. Am. Chem. Soc., 123, 4304 (2001); Inorg. Chem., 40, 1704
(2001)]. High efficiency electrophosphosecent organic light
emitting diodes emitting red, yellow, green, blue and white light
were carried out [Baldo, M. A., et al., Appl. Phys. Lett., 75, 4
(1999). Adachi, C., et Al., Appl. Phys. Lett., 77, 904 (2000).
Adachi, C., et al., Appl. Phys. Lett., 78, 1622 (2001). Adachi, C.,
et al., Appl. Phys. Lett., 79, 2082 (2001). D'Andrade, B. W., et
al., Adv. Mater., 14, 147(2002)]. These small organic complexes
were also blended with polymers and used for polymer light emitting
diodes [Lee, C., et al., Appl. Phys. Lett., 77, 2280 (2000). Zhu,
W., et al., Appl. Phys. Lett. 80, 2045 (2002]. Chen, F., et al.,
Appl. Phys. Lett., 80, 2308 (2002)]. However, these blend systems
always have phase separation problem and higher operation voltages
since large amount of small molecular charge transport materials
were added. The researchers in our laboratory have introduced
charge transport moieties into PPV via covalence bond to get
balance of charge injection and transport, and solve the phase
separation problem in physically blend system and simultaneously
simplify the device fabrication process (no need for additional
electron transport layer) [Lee, Y. et. al, J. Am. Chem. Soc., 123,
2296 (2001). U.S. Pat. No. 6,495,644 (2002)]. Thus it is highly
desirable to develop electroluminescent materials without phase
segregation problem, which can both utilize the high efficiency of
phosphorescent metal-organic complexes and carry charge transport
moiety for balancing the charge transport and injection.
SUMMARY OF THE INVENTION
[0003] The present invention synthesizes a novel electroluminescent
conjugated polymer grafted with a side chain comprising a
phosphorescent organometallic complex, and preferably further
grafted with another side chain comprising a charge transport
moiety. The electroluminescent conjugated polymer synthesized in
the present invention can be used to make a light emitting diode
emitting the light with broad band containing yellow, blue, green
and red peaks.
[0004] The conjugated polymer of the present invention comprising
repeating units represented by the following formula I, and its
molecular weight ranges from 1,000 to 2,000,000:
--(Ar.sup.1).sub.x--(Ar.sup.2).sub.y--(Ar.sup.3).sub.z--(Ar.sup.4).sub.p---
(Ar.sup.5).sub.q--(Ar.sup.6).sub.r-- (I)
[0005] wherein 0.ltoreq.x.ltoreq.1, 0.ltoreq.y.ltoreq.1,
0.ltoreq.z.ltoreq.1, 0.ltoreq.p.ltoreq.1, 0.ltoreq.q.ltoreq.1,
0.ltoreq.r.ltoreq.1; x+y+z+p+q+r=1, and x+y+z>0; Ar.sup.1,
Ar.sup.2, Ar.sup.3, Ar.sup.4, Ar.sup.5 and Ar.sup.6 are
independently selected from the group consisting of mono-,
bicyclic- and polycyclic aromatic groups; heterocyclic aromatic
group; substituted aromatic group; and substituted heterocyclic
aromatic group, provided that at least one of Ar.sup.1, Ar.sup.2
and Ar.sup.3 has a substituent comprising an organometallic
complex, such as an Ir-, Pt-, Os- and Rb-complex. Said substituent
further comprises a spacer which covalently bonds said
organometallic complex to the backbone of the polymer. Said
organometallic complex comprises an element of O, N, S, P, Cl, Br,
or C, and a heterocyclic ring, which coordinate the metallic
element of said organometallic complex. The heterocyclic ring may
be 2-phenylpyridine, 2-benzo[4,5-.alpha.]thienylpyridine,
(4,6-difluoro)phenylpyridine, 2-phenylbenzothiolate,
acetylacetonate, picolinate. Said spacer between said
organometallic complex and the backbone of the polymer includes
alkylene, alkylene containing heteroatoms, substituted alkylene,
substituted alkylene containing heteroatoms, an aromatic group, a
heterocyclic aromatic group, a substituted aromatic group, a
substituted heterocyclic aromatic group, and a combination thereof.
Ar.sup.1, Ar.sup.2 and Ar.sup.3 may separately contain
organometallic complexes emitting different light color peaks. For
example, the backbone of said conjugated polymer comprises two
different repeating units, each of which comprises a side chain,
each side chain comprising a phosphorescent organometallic complex,
wherein said two phosphorescent organometallic complexes are
different. Ar.sup.4 may contain a substituent having a hole
transport moiety. Suitable examples of the hole transport moiety
are a tertiary arylamine, a quarternary arylammonium salt, a
tertiary heterocyclic aromatic amine, a quarternary heterocyclic
aromatic ammonium, a substituted tertiary arylamine, a substituted
quarternary arylammonium salt, a substituted heterocyclic aromatic
amine, a substituted quarternary heterocyclic aromatic ammonium,
and a combination thereof. Preferably, carbazole or triphenylamine
is used as the hole transport moiety. The hole transport moiety is
bonded to the backbone of the polymer with a divalent radical,
which includes alkylene (such as decylene or hexylene), alkylene
containing heteroatoms, substituted alkylene, substituted alkylene
containing heteroatoms, an aromatic group, a heterocyclic aromatic
group, a substituted aromatic group, a substituted heterocyclic
aromatic group, and a combination thereof. Ar.sup.5 may contain a
substituent having an electron transport moiety, i.e. a high
eletronegative heterocyclic moiety, which includes (but not limited
to) a monoheterocyclic aromatic group, biheterocyclic aromatic
group and polyheterocyclic aromatic group containing an oxadiazole,
thiodiazole, triazole, pyridine, pyrimidine, or a combination
thereof. The electron transport moiety is bonded to the backbone of
the polymer with a divalent radical, which includes alkylene (such
as decylene or hexylene), alkylene containing heteroatoms,
substituted alkylene, substituted alkylene containing heteroatoms,
an aromatic group, a heterocyclic aromatic group, a substituted
aromatic group, a substituted heterocyclic aromatic group, and a
combination thereof. Ar.sup.6 may be grafted with a soluble
substituent of an alkyl, alkoxy, alkyl containing heteroatoms,
substituted alkyl, substituted alkyl containing heteroatoms, an
aromatic group, a heterocyclic aromatic group, a substituted
aromatic group, or a substituted heterocyclic aromatic group.
[0006] The present invention also discloses an organic light
emitting diode, which comprises: a positive electrode formed on a
substrate; a negative electrode; and a light emitting layer
disposed between said positive electrode and said negative
electrode, wherein said light emitting layer comprises the
electroluminescent conjugated polymer of the present invention.
[0007] Preferably, the organic light emitting diode further
comprises an electron injection layer formed between said light
emitting layer and said negative electrode.
[0008] Preferably, the organic light emitting diode further
comprises a hole transporting layer formed between said positive
electrode and said light emitting layer.
[0009] Preferably, the organic light emitting diode is able to emit
red light, yellow light, green light, blue light, white light or
light with broad band containing multiple color peaks.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a plot showing the relationship between current
density-voltage-brightness of a polymer light-emitting diode
(PLED), ITO/PEDOT/CzPFR1.3/Ca/Al, prepared in Example 16 of the
present invention.
[0011] FIG. 2 shows an electroluminescent (EL) spectrum of the PLED
in FIG. 1.
[0012] FIG. 3 shows an electroluminescent (EL) spectrum of a PLED,
ITO/PEDOT/PPFPtY/Ca/Al, prepared in Example 16 of the present
invention.
[0013] FIG. 4 shows an electroluminescent (EL) spectrum of a PLED,
ITO/PEDOT/CzPFR08/Ca/Al, prepared in Example 16 of the present
invention.
DETAILED DESCRIPTION OF THE INVENTION
[0014] The present invention discloses a conjugated polymer
comprising repeating units represented by the aforesaid formula
(I). The repeating units of the polymer, Ar.sup.1, Ar.sup.2,
Ar.sup.3, Ar.sup.4, Ar.sup.5 and Ar.sup.6, may be identical or
different. The backbone of the polymer of the present invention may
be represented by but is not limited to the following structures
(II):
[0015] The structures (II): repeating units of the backbone of the
polymer 12345
[0016] At least of the repeating units of Ar.sup.1, Ar.sup.2 and
Ar.sup.3 contains a substituent comprising an organometallic
complex. Suitable examples of said organometallic complex are those
represented by but are not limited to the following structures
(III):
[0017] The structures (III): organometallic complex 6
[0018] wherein R is alkyl or aryl, which may be different;
78910111213
[0019] The polymer of the present invention may have one type of
organometallic complex, two or more than two types of
organometallic complexes.
[0020] The repeating units Ar.sup.4 and Ar.sup.5 of the polymer of
the present invention may contain a hole transport moiety and an
electron transport moiety, respectively. Suitable hole transport
moiety and electron transport moiety includes (but not limited to)
the following structures (IV) and (V):
[0021] The structure (IV): hole transport moiety 14
[0022] wherein m=1.about.5, n=1.about.4, o=1.about.3, p=1.about.2,
R is C.sub.1.about.C.sub.22 alkyl, C.sub.1.about.C.sub.22 alkoxy,
C.sub.1.about.C.sub.22 alkylthio,
--NR.sup.I.sub.3.sup.+(R.sup.I=C.sub.1.- about.C.sub.22),
--NR.sup.I.sub.2(R.sup.I=C.sub.1.about.C.sub.22),
--SiR.sup.I.sub.3(R.sup.I=C.sub.1.about.C.sub.22), or other soluble
groups, wherein R may be identical or different either on the same
ring or different rings.
[0023] The structure (V): electron transport moiety 1516
[0024] wherein m=1.about.5, n=1.about.4, o=1.about.3, p=1.about.2,
R is C.sub.1.about.C.sub.22 alkyl, C.sub.1.about.C.sub.22 alkoxy,
C.sub.1.about.C.sub.22 alkylthio,
--NR.sup.I.sub.3.sup.+(R.sup.I=C.sub.1.- about.C.sub.22),
--NR.sup.I.sub.2(R.sup.I=C.sub.1.about.C.sub.22),
--SiR.sup.I.sub.3(R.sup.I=C.sub.1.about.C.sub.22) or other soluble
groups, wherein R may be identical or different either on the same
ring or different rings; X=O, S, or N--R.sup.II, wherein R.sup.II
is C.sub.1.about.C.sub.22 alkyl, C.sub.1.about.C.sub.22 alkoxy,
phenyl, C.sub.7.about.C.sub.28 alkylaryl, C.sub.7.about.C.sub.28
alkoxyaryl, phenoxy, C.sub.7.about.C.sub.28 alkylphenoxy,
C.sub.7.about.C.sub.28 alkoxyphenoxy, diphenyl, diphenoxy,
C.sub.13.about.C.sub.34 alkyldiphenyl, C.sub.13.about.C.sub.34
alkoxydiphenyl, C.sub.13.about.C.sub.34 alkyldiphenoxy, or
C.sub.13.about.C.sub.34 alkoxydiphenoxy.
[0025] The polymer of the present invention may have one type of
charge transport moiety, two or more than two types of charge
transport moieties.
[0026] The repeating unit Ar.sup.6 of the polymer of the present
invention may have a side-chain substituent selected from
C.sub.1.about.C.sub.22 alkyl, C.sub.1.about.C.sub.22 alkoxy,
C.sub.1.about.C.sub.22 alkylthio,
--NR.sup.I.sub.3.sup.+(R.sup.I=C.sub.1.about.C.sub.22),
--NR.sup.I.sub.2(R.sup.I=C.sub.1.about.C.sub.22), --SiR.sup.I.sub.3
(R.sup.I=C.sub.1.about.C.sub.22), phenyl, C.sub.7.about.C28
alkylaryl, C.sub.7.about.C.sub.28 alkoxyaryl, phenoxy,
C.sub.7.about.C.sub.28 alkylphenoxy, C.sub.7.about.C.sub.28
alkoxyphenoxy, diphenyl, diphenoxy, C.sub.13.about.C.sub.34
alkyldiphenyl, C.sub.13.about.C.sub.34 alkoxydiphenyl,
C.sub.13.about.C.sub.34 alkyldiphenoxy, C.sub.13.about.C.sub.34
alkoxydiphenoxy. or other soluble groups.
[0027] The organometallic complex or charge transport moiety is
bonded to the backbone of the polymer of the present invention with
a spacer. Suitable spacers include C.sub.1.about.C.sub.22 alkylene,
C.sub.1.about.C.sub.22 alkylene containing heteroatoms, substituted
C.sub.1.about.C.sub.22 alkylene, substituted C.sub.1.about.C.sub.22
alkylene containing heteroatoms, C.sub.5.about.C.sub.22 aromatic
group, C.sub.4.about.C.sub.22 heterocyclic aromatic group,
C.sub.5.about.C.sub.22 substituted aromatic group,
C.sub.4.about.C.sub.22 substituted heterocyclic aromatic group, and
a combination thereof.
[0028] The polymer of the present invention can be a homopolymer or
a copolymer, which can be a random copolymer, block copolymer or
alternating copolymer. The copolymer may comprise a non-conjugated
sector among two or more conjugated sectors in a backbone of said
copolymer. In the backbone of the polymer of the present invention
the repeating unit containing the organometallic complex ranges
from 0.05 to 100 mol %, preferably from 0.1 to 20 mol %, and more
preferably from 0.5 to 10 mol %; the repeating unit containing the
charge transport moiety ranges from 0 to 99.95 mol %; and the
repeating unit containing other substituent ranges from 0 to 99.95
mol %.
[0029] Preferably, the polymer of the present invention further
comprises a crosslinkable or printable functional group
[0030] Preferably, the polymer of the present invention has a
number average molecular weight of 1,000.about.2,000,000, more
preferably 5,000.about.1,000,000, and most preferably
10,000.about.600,000.
[0031] Examples of the polymer of the present invention are shown
by the following structures (VI) to (VIII):
[0032] The structure (VI): polymers CzPFR1.3 and CzPFR08 17
[0033] wherein the polymer CzPFR1.3 has x=1.3%, and y=98.7%; the
polymer zPFR08 has x=0.8%, and y=99.2%.
[0034] The structure (VII): polymer PFOR1 18
[0035] wherein x=1%, and y=99%.
[0036] The structure (VIII): polymer PFOG05R01 19
[0037] The present invention will be elucidated by the following
examples, which are illustrative only and not for limiting the
scope of the present invention.
[0038] The polymer of the present invention can be synthesized by
copolymerizing suitable monomers which are able to form a
conjugated polymer, for example, via the coupling reactions
disclosed by Suzuki or Yamamoto. The following compounds are
examples of the suitable monomers for synthesis of the polymer of
the present invention, which are merely illustrative and not for
restricting the scope of the present invention: 2021
[0039] The synthetic routes for the compounds prepared in the
following Examples 1 to 5 and 7 compounds are shown in Scheme 1.
2223
EXAMPLE 1
[0040] 12-bromododecan-2-one (1). 11-Bromoundecanoic acid (37.7
mmol, 10 g) was dissolved in THF (300 mL). The solution was cooled
to -78.degree. C., and a 1.6 M solution of CH.sub.3Li (75.4 mmol,
47.1 mL) in diethylether was added dropwisely. The reaction mixture
was allowed to warm to 0.degree. C. and quenched with saturated
ammonium chloride followed by extraction with ether. The ether
phase was separated, dried over MgSO.sub.4, and concentrated.
Purification by silica gel column chromatography (hexane/ethyl
acetate) gave 6.9 g (yield 70%) of a colorless oil. The compound
(1) was confirmed by GC/MS (m/z=262).
EXAMPLE 2
[0041] 9-hexylfluorene (2). To a solution of fluorene (33.2 g, 0.20
mol) in 300 mL THF at -78.degree. C., n-butyllithium (2.5 M, 80 mL)
was added dropwisely. The mixture was stirred at -50.degree. C. for
45 minutes, and then cooled to -78.degree. C. again and
n-hexylbromide (33.0 g, 0.20 mol) in THF (25 mL) was added dropwise
to the mixture. The solution was allowed to warm up to room
temperature and stirred for 5 h. The mixture was then poured into
water and extracted with ether. The organic extracts were washed
with brine and dried over magnesium sulfate, and purified by silica
gel column with hexane to give pure compound 2 (38 g, yield
76%).
EXAMPLE 3
[0042] 2,7-dibromo-9-hexylfluorene (3). To a solution of
9-hexylfluorene (38.0 g, 0.158 mol) in 200 mL chloroform at
-78.degree. C., ferric chloride (400 mg) and
2,6-di-t-butyl-4-methylphenol (20 mg) were added. Bromine (17.2 mL,
0.335 mol) was added dropwisely to the mixture while keeping all in
the dark. The mixture was warmed to room temperature and stirred
overnight. The resulting slurry was poured into water (300 mL). The
aqueous layer was extracted with chloroform, and the combined
organic phase was washed with aqueous sodium thiosulfate until the
red color disappeared. The crude product was recrystallized from
ethanol twice to give a colorless crystal (57 g, yield 88%).
EXAMPLE 4
[0043] 9-n-hexyl-9-(11-oxo-dodecan-one)-2,7-dibromofluorene (4). To
a solution of 2,7-dibromo-9-hexylfluorene (49.0 mmol, 20.0 g) in
THF, sodium hydride (98 mmol, 2.35 g) was added. The mixture was
refluxed for 1 h under N.sub.2 atmosphere; and
12-bromododecan-2-one (1) (49.0 mmol, 12.8 g) was added dropwisely.
The mixture was refluxed for 12 h and then cooled to room
temperature. Then it was filtered to remove the insoluble material
and the solvent was removed by vacuum. The crude product was
purified by silica column chromatography (85:15
hexane/ethylacetate) to afford 20 g (yield 70%) of the compound
(4). .sup.1H NMR (CDCl.sub.3) .delta. (ppm): 7.36-7.45 (m, 6H),
2.32 (t, 2H), 2.02 (s, 3H), 1.87-1.89 (m, 4H), 0.55-1.47 (m, 27H);
.sup.13C NMR (CDCl.sub.3) .delta. 208.37, 152.18, 138.70, 129.86,
125.84, 121.22, 120.85, 55.33, 43.35, 39.84, 31.10, 29.01-29.48,
28.43-28.81, 27.83, 23.31-23.43, 22.25, 13.73.
EXAMPLE 5
[0044] 9-hexyl-9-(11,13-dioxo-tetradecyl)-2,7-dibromofluorene (5).
2,7-dibromo-9- hexylfluorene (10 mmol, 6.0 g) and ethylacetate (25
mL) were mixed and cooled to 0.degree. C. Sodium (20 mmol, 0.46 g)
was added. The mixture was refluxed for 12 h, cooled and poured
into ice. The organic layers were separated and washed three times
with water. The combined aqueous layers were acidified with diluted
acetic acid. The diketone (5) was extracted with ether and purified
by silica column chromatography to afford as an oil 4.8 g (yield
75%). .sup.1H NMR (CDCl.sub.3) .delta. (ppm): 7.38-7.46 (m, 6H),
5.42 (s, .about.0.83H, enol form), 3.51 (s, 0.26H. keto form), 2.18
(t, 2H), 1.97 (s, 3H), 1.88 (t, 4H), 1.54-0.56 (m, 27H); .sup.13C
NMR(CDC1.sub.3) .delta. 203.85 and 201.72 (keto form), 193.96 and
191.04 (enol form), 152.27, 138.79, 129.93, 125.92, 121.29, 120.91,
99.49, 55.41, 43.52, 39.94, 39.85, 37.99, 31.20, 29.57-29.03,
28.95-28.74, 25.78, 23.42-23.11, 22.33, 13.79.
EXAMPLE 6
[0045] Chloride-bridged dimer
[(btp).sub.2Ir-(.mu.-Cl).sub.2Ir(btp).sub.2(- 6a),
btp=2-benzo[4,5-.]thienylpyridine] and
[(ppy).sub.2Ir-(.mu.-Cl).sub.2- Ir(ppy).sub.2(6b),
ppy=2-phenylpyridine]. 6a and 6b were synthesized by the method
reported by Nonoyama (Nonoyama, M. Bull. Chem. Soc. Jpn. 1974, 47,
767.), which involves refluxing IrCl.sub.3.nH.sub.2O with
2.about.2.5 equiv of cyclometalating ligand (btp or ppy) in a 3:1
mixture of 2-methoxyethanol and water.
EXAMPLE 7
[0046] Ir red complex monomer
9-hexyl-9-(iridium(III)bis(2-(2'-benzo[4,5-.-
]thienyl)pyridinato-N,C.sup.3')
(tetradecanedionate-11,13)-2,7-dibromofluo- rene (7a).
Chloride-bridged dimer 6a (0.74 g, 0.57 mmol) of, 4 (0.90 g, 1.422
mmol) and sodium carbonate (100 mg) were mixed and refluxed under
N.sub.2 atmosphere in 2-ethoxyethanol for 15 h. The solution was
cooled to room temperature, and the colored precipitate was
filtered and washed with water and hexane. The crude product was
subjected to chromatographic work up using a silica/dichloromethane
column to yield ca. (75-80%) of the compound (7a). It was further
purified by TLC plate (30% dichloromethane and 70% hexane). .sup.1H
NMR (CDCl.sub.3) .delta. (ppm): 8.41 (d, 2H), 7.71 (t, 2H),
7.44-7.64 (m, 10H), 7.06 (t, 2H), 6.95 (t, 2H), 6.82 (t, 2H), 6.29
(d, 1H), 6.22 (d, 1H), 5.24 (s, 1H), 1.98 (m, 6H), 1.80 (s, 3H),
1.48-0.60 (m, 27H); .sup.13C NMR (CDCl.sub.3) .delta. (ppm):
188.34, 184.55, 166.05, 152.49, 149,18, 149.09, 146.90, 146.78,
146.50, 146.26, 142.29, 142.14, 137.94, 135.04, 130.13, 126.10,
125.74, 124.82, 123.52, 122.63, 121.15, 100.22, 55.60, 41.33,
40.17, 31.42, 29.93-28.47, 27.02, 23.65, 22.69-22.54, 13.96. Anal.
Calcd: C, 56.95; H, 4.78; N, 2.25, S, 5.15; Found: C, 58.15; H,
5.06; N, 2.24; S, 5.09.
[0047] High-resolution MS: calculated M.sup.+ 1244.1964; observed
M.sup.+ 1244.2001.
[0048] Ir green complex monomer 9-hexyl-9-(iridium(III)bis(2-phenyl
pyridinato-N,C.sup.2')(tetradecanedionate-11,13)-2,7-dibromofluorene
(7b). Similar to the method for 7a, 4 (0.90 g, 1.42 mmol) and 6b
(0.5 g, 0.51 mmol) and sodium carbonate (100 mg) were used for the
preparation. .sup.1H NMR (CDCl.sub.3) .delta. (ppm): 8.46 (d, 2H),
7.43.about.7.69 (m, 12H), 7.07 (m, 2H), 6.77 (m, 2H), 6.66 (m, 2H),
6.32 (d, 1H), 6.23 (d, 1H), 5.16(s, 1H), 1.95 (m, 6H), 1.89 (s,
3H), 1.22 (b, 3H), 0.99.about.1.20 (m, 18H), 0.77 (m, 2H), 0.61 (b,
4H). .sup.13C NMR (CDCl.sub.3) .delta. (ppm): 188.35, 184.59,
168.61, 168.52, 152.92, 152.51, 150.62, 150.26, 148.23, 148.16,
147.93, 147.80, 144.75, 144.70, 141.07, 140.12, 140.00, 139.04,
136.73, 136.67, 133.31, 133.03, 129.86, 129.06, 128.94, 127.45,
126.95, 126.91, 126.66, 126.13, 126.09, 123.80, 123.64, 122.83,
122.79, 121.44, 121.31, 121.18, 121.02, 120.93, 120.64, 120.60,
119.73, 119.61, 118.32, 118.11, 100.00, 55.66, 55.34, 54.97, 41.64,
40.38, 40.26, 40.19, 31.44, 30.03, 29.94, 29.85, 29.68, 29.60,
29.53, 29.48, 29.36, 29.22, 28.81, 28.75, 27.10, 23.75, 23.68,
23.63, 22.53, 13.96. High-resolution MS: calculated M.sup.+
1132.2552; observed M.sup.+ 1132.2560.
[0049] The synthetic routes for the compounds synthesized in
Examples 8-11 are shown in Scheme 2. 24
EXAMPLE 8
[0050] N-(10-bromodecyl)-carbazole (8). 10 g (0.25 mol) sodium
hydride (60%) was added in several portions into a solution of 30.6
g (0.20 mol) carbazole in 200 mL THF. Then the mixture was
transferred into a funnel from which it was added dropwisely into a
solution of 180 g (0.6 mol) dibromodecane in 500 mL THF at
70.degree. C. and the mixture was refluxed for 48 h. After cooling,
it was filtered. The filtrate was distilled in order to remove
remaining dibromodecane. The residue was diluted with water and
extracted with CH.sub.2Cl.sub.2. The organics was washed with brine
and dried over anhydrous MgSO.sub.4 overnight. After removed the
solvent by rotary evaporator, it was purified by silica
chromography to give 31.6 g (41%, yield, mp 38.about.40.degree. C.)
white solid product. .sup.1H NMR (500 MHz, CDCl.sub.3), .delta.
(ppm): 8.14 (2H, d), 7.51 (2H, d), 7.44 (2H, d), 7.26 (2H, d), 4.30
(2H, t), 3.41 (2H, t), 1.27.about.1.90 (16H, m).
EXAMPLE 9
[0051] 9,9-di-(n-octyl)-2,7-dibromofluorene (9a). To a solution of
28.5 g (88 mmol) 2,7-dibromofluorene in 800 mL THF was added 8.8 g
(220 mmol) sodium hydride (60%) in several portions at room
temperature. The mixture was heated at 60.degree. C. and 43 g (220
mmol) bromooctane in 200 mL THF was added dropwisely into the
mixture and refluxed overnight. The mixture was concentrated and
diluted with water, and then extracted with diethyl ether. After
washing with brine, the ether solution was dried over anhydrous
MgSO.sub.4 and the ether was then removed by evaporation. This
crude solid was purified by a silica chromography with hexane and
recrystallized from ethanol to give white solid (36.3 g, yield
75.3%, mp. 52.about.54.degree. C.). .sup.1H NMR (500 MHz,
CDCl.sub.3), .delta. (ppm): 7.51 (2H, d), 7.44 (2H, d), 7.41 (2H,
s), 1.89 (4H, m), 1.02.about.1.20 (20H, m), 0.81 (6H, t), 0.56 (4H,
m).
[0052] 9,9-Bis(N-carbazolyl-decyl)-2,7-dibromofluorene (9b). To a
mixture of 5.2 g (16 mmol) 2,7-dibromofluorene in 300 mL THF was
added 1.3 g (41 mmol) sodium hydride (75%) in several portions. A
mixture of 15 g (39 mol) N-(10-bromodecyl)-carbazole (8) in 100 mL
THF was added dropwisely at 70.degree. C. and the mixture was
refluxed for 48 h. After cooling, the solid was filtered and the
filtrate was concentrated and dilute with water and extracted with
CH.sub.2Cl.sub.2. The organic layer was collected and washed with
brine and dried with anhydrous MgSO.sub.4. The crude product was
further purified by silica column chromography to give 5.1 g (yield
34%, mp 94.about.96.degree. C.) title product. .sup.1H NMR
(CDCl.sub.3), .delta. (ppm): 8.10 (4H, d), 7.38.about.7.48 (14H,
m), 7.23 (4H, t), 4.27 (4H, t), 0.88.about.1.86 (36H, m). Anal.
Calcd: C, 73.22; H, 6.68; N, 3.00. Found: C, 72.58; H, 6.59; N,
2.73.
EXAMPLE 10
[0053] 9,9-dioctylfluorene-2,7-diboronic acid (10). A mixture of 11
g (20 mmol) 9,9-di-(n-octyl)-2,7-dibromofluorene (9a), 1.44 g (60
mmol) magnesium turning and a catalytic amount of iodine in 50 mL
dried ThF under argon was heated carefully to form a Grignard
reagent. The reagent was then transferred to a stirred solution of
34 mL (200 mmol) triethyl borate in dry THF at -78.degree. C. over
a period of 2 h. The mixture was then slowly warmed to room
temperature and kept stirring for 2 days. It was then poured into
cold 2 N HCl while stirring. The mixture was extracted with ether
and washed with brine, and dried. The crude solid was then purified
by silica column chromography to give a white product (2.96 g,
yield 31%). .sup.1H NMR (DMSO-d6), .delta. (ppm): 8.01 (4H, s),
7.82 (2H, s), 7.73 (4H, d), 1.94 (4H, m), 1.04.about.1.14 (20H, m),
0.76 (6H, t), 0.46 (4H, m).
EXAMPLE 11
[0054] 9,9-dioctylfluorene-2,7-bis(trimethylene boronate) (11). A
mixture of 2.77 g (5.80 mmol) 9,9-dioctylfluorene-2,7-diboronic
acid (10) and 7 g (9 mmol) 1,3-propylenediol in 200 mL toluene was
refluxed for 10 h. The organic layer was washed with brine and
concentrated to give a white solid. It was then recrystallized from
hexane to give 2.5 g (yield 76%, mp. 120.about.122.degree. C.)
product. .sup.1H NMR (CDCl.sub.3), .delta. (ppm): 7.73 (2H, d),
7.70 (2H, s), 7.67 (2H, d), 4.18 (8H, t), 2.07 (4H, m), 1.96 (4H,
m), 10.78.about.1.24 (30H, m).
[0055] The synthetic route for the polymers prepared in Example 12
is shown in Schemes 3 and 4. 25 26
EXAMPLE 12
General Procedures of Polymerization for Polymers without Cz Group
by Suzuki Cross Coupling Method, Taking PFO as an Example
[0056] To a bottle with 9,9-dioctylfluorene-2,7-bis(trimethylene
boronate) (0.584 g, 1.05 mmol), 2,7-dibromo-9,9-di-n-octylfluorene
(0.576 g, 1.05 mmol), tetrakis-(triphenylphosphine)palladium (3 mg)
and potassium carbonate (0.52 g, 3.8 mmol) were added Aliquat 336
(0.10 g, 0.25 mmol) in toluene (10 mL) and degassed water (1.8 mL)
by syringe under argon. The mixture was stirred and heated at
85.degree. C. for 5 days. Then, the polymer was capped by adding
0.1 mL of phenyl-dioxopropyleneboronate followed by heating for one
day and 0.2 mL of p-(t-butyl)bromobenzene followed by heating for
another day. The mixture was poured into methanol. The precipitate
was collected by filtration and dried and then re-dissolved in THF,
and again precipitated in methanol followed by washing and drying.
.sup.1H NMR: (CDCl.sub.3), .delta. (ppm): 7.81 (d, 2H), 7.68 (m,
4H), 2.11 (m, 4H), 1.12.about.1.24 (m, 20H), 0.79.about.0.92 (m,
10H). .sup.13C NMR (CDCl.sub.3) .delta. (ppm): 151.79, 140.48,
140.00, 126.15, 121.47, 119.95, 61, 55.32, 40.38, 31.78, 30.02,
29.21, 23.90, 22.59, 14.06. Anal. Calcd for C.sub.29H.sub.40: C,
89.62; H, 10.38. Found: C, 88.85; H, 10.09. The yields for the
polymer PFO and the following polymers by the Suzuki method were in
the range 60.about.90%.
[0057] PFOR01: .sup.1H NMR: (CDCl.sub.3), .delta. (ppm): 7.82 (d,
2H), 7.68 (m, 4H), 2.11 (m, 4H), 1.12.about.1.55 (m, 20H),
0.78.about.0.82 (m, 10H). Anal. Calcd: C, 89.56; H, 10.36; Found:
C, 88.28; H, 10.33.
[0058] PFOR1: .sup.1H NMR: (CDCl.sub.3) .delta. (ppm): 7.82 (d,
2H), 7.68 (m, 4H), 2.11 (m, 4H), 1.12.about.1.54 (m, 20H),
0.77.about.0.81 (m, 10H). Anal. Calcd: C, 88.96; H, 10.24; Found:
C, 87.30; H, 10.72.
[0059] PFOR12: .sup.1H NMR: (CDCl.sub.3), .delta. (ppm): 7.82 (d,
2H), 7.68 (m, 4H), 2.11 (m, 4H), 1.12.about.1.54 (m, 20H),
0.78.about.0.81 (m, 10H). 8.41 (s, 7%.times.1H), 7.03 (m,
7%.times.2H), 6.93 (m, 7%.times.2H), 6.78 (m, 7%.times.2H), 6.25
(d, 7%.times.1H), 6.18 (d, 7%.times.1H), 5.19 (s, 7%.times.1H).
Anal. Calcd: C, 82.93; H, 9.03; N, 0.71; S, 1.63. Found: C, 84.43;
H, 9.02; N, 0.22; S, 0.60. According to the NMR data, the
Ir-content in the copolymer is around 7%.
[0060] PFOG05R01: .sup.1H NMR: (CDCl.sub.3), .delta. (ppm): 7.82
(d, 2H), 7.68 (m, 4H), 2.11 (m, 4H), 1.12.about.1.54 (m, 20H),
0.77.about.0.81 (m, 10H). Anal. Calcd: C, 89.32; H, 10.31; Found:
C, 86.17; H, 10.16.
[0061] The synthetic route for the polymers prepared in Example 13
is shown in Scheme 5. 2728
EXAMPLE 13
General Procedures of Polymerization for Polymers with Cz Group by
the Yamamoto Reaction, Taking Cz100PF as an Example
[0062] Into a reactor, bis(1,5-cyclooctadiene) nickel (0)
(Ni(COD).sub.2) (0.846 g, 3.08 mmol), 2,2-bipyridyl (BPY) (0.480 g,
3.08 mmol), 1,5-cyclooctadiene (COD) (0.334 g, 3.08 mmol) and
anhydrous DMF (3 mL) were added in a dry box with nitrogen. This
mixture was stirred at 80.degree. C. for 30 min to form active
catalyst. The monomer 9,9-bis
(N-carbazolyl-decyl)-2,7-dibromofluorene (2 mmol) in 12 mL of
anhydrous toluene was added to the mixture. The polymerization
proceeded at 80.degree. C. for 6 days in the dry box, then
1-bromo-4-tert-butylbenzene as end-capping agent (0.2 mmol, 378. L)
was added to continually react for 24 h. The resulting polymer was
purified by alumina oxide chromatography and precipitated in
acetone/methanol (volume ratio=1:1) and finally dried under vacuum
for 24 h. .sup.1H-NMR (500 MHz, CDCl.sub.3), .delta. (ppm): 8.04
(t, 4H), 7.75 (d, 2H), 7.64 (s, 4H), 7.13.about.7.40 (m, 12H), 4.14
(t, 4H), 2.03 (b), 1.71 (m, 4H), 0.76.about.1.23 (m, 32H). .sup.13C
NMR (CDCl.sub.3) .delta. (ppm): 140.34, 125.50, 122.74, 120.28,
118.63, 108.59, 42.95, 29.94, 29.41, 29.35, 29.78, 29.12, 28.85,
27.20. Anal. Calcd: C, 88.37; H, 8.01; N 3.62. Found: C, 87.66; H,
8.19; N, 3.10. The yields for the polymer Cz100PF and the following
polymers by the Yamamoto method were in the range 80.about.85%.
[0063] CzPFR08: .sup.1H-NMR (CDCl.sub.3), .delta. (ppm): 8.03 (d,
4H), 7.75 (d, 2H), 7.65 (s, 4H), 7.13.about.7.38 (m, 12H), 4.14 (t,
4H), 1.71 (m, 4H), 0.77.about.1.24 (m, 32H). .sup.13C NMR
(CDCl.sub.3) .delta. (ppm): 140.36, 125.50, 122.76, 120.29, 118.64,
108.59, 42.95, 29.94, 29.41, 29.34, 29.78, 29.12, 28.85, 27.21.
Anal. Calcd: C, 88.12; H, 7.98; N, 3.61. Found: C, 88.29; H, 8.09;
N, 3.42.
[0064] CzPFR13: .sup.1H-NMR (CDCl.sub.3), .delta. (ppm): 8.03 (d,
4H), 7.75 (d, 2H), 7.65 (s, 4H), 7.13.about.7.38 (m, 12H), 4.14 (t,
4H), 1.72 (t, 4H), 0.77.about.1.24 (m, 32H). .sup.13C NMR
(CDCl.sub.3) .delta. (ppm): 151, 140.36, 125.50, 122.76, 120.28,
118.64, 108.59, 55, 42.95, 29.94, 29.41, 29.34, 29.78, 29.12,
28.85, 27.21. Anal. Calcd: C, 87.96; H, 7.97; N, 3.60. Found: C,
88.10; H, 8.11; N, 3.23.
[0065] The actual compositions of the polymers are somewhat
different from the feed ratios used. The Ir-complex content in
PFOR12 is about 7 mol % according to the NMR measurement. The
weight average molecular weight and polydipersity (PDI) of the
polyfluorenes synthesized are shown in the following Table.
1 Polymer Mw (10.sup.4) PDI PFO 16.0 3.21 PFOR01 7.1 2.54 PFOR1 7.4
1.99 PFOR12 13.0 3.58 PFOG05R01 2.5 1.87 Cz100PF 8.5 2.79 CzPFR08
12.5 2.47 CzPFR1.3 15.4 2.73
EXAMPLE 14
[0066] 14-(2,5-dibromo-4-butoxy-phenoxy)-tetradecane-2,4-dione. To
a solution of 12-(2,5-dibromo-4butoxy-phenoxy)-dodecan-2-one (12.5
mmol, 6.3 g) in 50 mL ethyl acetate Na (24.9 mmol, 573 mg) was
added. The mixture was refluxed for 12 h and then cooled to room
temperature. The reaction was stopped by adding ice to the mixture,
which was then neutralized by adding a diluted H.sub.2SO.sub.4, and
extracted with ether. The crude product was purified by silica
chromatography to obtain a yellow solid 3.42 g (yield 50%). The
structure was confirmed by NMR.
[0067] Pt yellow complex monomer 1-butoxy-4-(platinum(II)
bis(2-phenylbenzothiazolato-N,C.sup.2'))(tetradecanedionate-11,13)-2,5-di-
bromobenzene. K.sub.2PtCl.sub.4 salt (0.48 mmol, 200 mg) and 2.5
equivalent cyclometalating ligand 2-phenylbenzothiazole (1.2 mmol,
254 mg) were dissolved in the mixture of 2-ethoxyethanol (15 mL)
and water (5 mL) (3:1 by weight) and allowed to react at 80.degree.
C. for 16 hrs. To the resulting solution after cooling down to room
temperature, 10 equivalent K.sub.2CO.sub.3 (4.8 mmol, 663 mg) and
2.5 equivalent
14-(2,5-dibromo-4-butoxy-phenoxy)-tetradecane-2,4-dione (1.2 mmol,
658 mg) were added and the reaction was carried out at 100.degree.
C. for 16 hrs. After cooling down to room temperature, the solvent
was removed in vacuo. The crude product was purified by flash
chromatography using dichloromethane as eluent and then further
recrystallized with dichloromethane/methanol mixture. The product
so obtained is yellow solid and the yield is 9.6%.
EXAMPLE 15
[0068] Polymer PPFPtY. This polymer was prepared by using the
procedures similar to those described in Example 12.
1-Butoxy-4-(platinum(II) bis(2-phenylbenzothiazolato-N,C.sup.2'))
(tetradecanedionate-11,13)-2,5-d- ibromobenzene (6.05 mol) prepared
in Example 14 and 2,7-dibromo-9,9-di-n-octylfluorene (0.5 mmol)
were used.
EXAMPLE 16
[0069] Device fabrication and characterization. An indium-tin oxide
(ITO) glass plate was exposed on oxygen plasma at a power of 30 W
and a pressure of 200 mTorr for 5 minutes. A thin hole injection
layer (40 nm) of poly(styrene sulfonic acid) doped
poly(ethylenedioxythiophene) (PEDOT-PSS) (Baytron P CH 8000 from
Bayer, its conductivity is 10.sup.-5 S/cm.) was spin-coated on the
treated ITO. On top of it, a thin layer (80.about.120 nm) of the
polyfluorene prepared in Examples 13 or 15 of the present invention
was spin-cast from its solution in THF (7.about.10 mg/mL). Finally,
a thin layer of calcium (about 5 nm) covered with a layer of
aluminum was deposited in a vacuum thermal evaporator through a
shadow mask at a pressure of less than 10.sup.-6 Torr. The active
area of the diode is about 10 mm.sup.2.
[0070] FIG. 1 is a plot showing the relationship between current
density-voltage-brightness of a polymer light-emitting diode
(PLED), ITO/PEDOT/CzPFR1.3/Ca/Al, prepared above. This PLED device
emits red light after being subjected to a positive bias, and its
electroluminescent (EL) spectrum is shown in FIG. 2. This PLED
device has a turn-on voltage about 4.9 V, a maximum efficiency of
2.8 cd/A at 7 V, which remains high (1.6 cd/A at 15 V and 4321
cd/m.sup.2), and a maximum brightness of 4321 cd/m.sup.2.
[0071] FIG. 3 shows an electroluminescent (EL) spectrum of a
polymer light-emitting diode (PLED), ITO/PEDOT/PPFPtY/Ca/Al,
prepared above. This PLED device emits yellow light.
[0072] FIG. 4 shows an electroluminescent (EL) spectrum of a
polymer light-emitting diode (PLED), ITO/PEDOT/CzPFR08/Ca/Al,
prepared above. This PLED device emits light with broad band
containing multiple color peaks.
* * * * *